Fluid leakage can occur in high-pressure pumps especially after extended use as pump components wear with age. For instance, in liquid chromatography systems, generally, one or more high-pressure pumps take in solvents and deliver a liquid solvent composition to a sample manager, where a sample awaits injection into a mixture. High-performance liquid chromatography (HPLC) systems use high pressure, ranging traditionally between 1,000 to 6,000 psi, to generate the flow required for liquid chromatography in packed columns. In contrast to HPLC, ultra-performance liquid chromatography (UPLC) systems use columns with smaller particulate matter and high pressures that can reach or exceed 20,000 psi to deliver a mobile phase. In many liquid chromatography systems, two or more pumps are employed in a serial or parallel configuration.
In various liquid chromatography applications, a high-pressure seal resides within a gland in either a pump head or a seal wash housing. Over time the seal may wear, causing fluid to leak from the pump head. Diagnostic testing may not be able to identify the failure mode, that is, the cause and source of the leak. For example, the leak may occur at the inside diameter (ID) or the outside diameter (OD) of the high-pressure seal, or at another component such as a check valve or a vent valve.